The present invention relates to a cleansing composition.
Conventionally, as skin cleansing agents, anionic surfactants such as alkyl sulfate, polyoxyethylene alkyl sulfate, and higher fatty acid salts have been used. However, use of such surfactants presents problems such a slimy feeling during rinsing and a tight feeling after use, as in JP-A-2007-112984 and JP-A-H11-508268. Also, it has occasionally been observed that when these skin cleansing agents are applied by hand, pimples appear in areas that are difficult to reach by hand, such as the back. One possible reason for the foregoing difficulties is that sebum cannot be completely washed off and thus accumulates on the skin. In view of the above, a cleansing agent which is less irritating to the skin and has a good ability to wash off sebum (i.e., sebum cleansing properties) is desired.
Although alkyl ether carboxylic acid-based surfactants are known to be gentle to the skin, they have poor foaming properties. Thus, the use of these surfactants in combination with other surfactants such as alkyl ether sulfates has been considered. However, when such combinations of surfactants have been used, a feeling that rinsing has concluded, i.e., a feeling of friction during rinsing, is lessened. In view of this difficulty, various attempts to improve the rinsing properties of such combinations of surfactants have been made, as, for example, in JP-A-2008-285479.
Also, attempts have been made to prepare cleansing compositions containing an ether carboxylic acid-based surfactant having improved foamability. Such cleansing compositions have included ether carboxylic acid-based surfactants with narrow molecular weight distribution, as in JP-A-S61-21199 and JP-A-2001-207189. Further, a cleansing composition containing an ether carboxylic acid-based surfactant having a specific distribution of added moles of ethylene oxide has been proposed, as in JP-A-H02-175799.
Notwithstanding the foregoing efforts, known cleansing compositions remain unsatisfactory with respect to the amount of time required to obtain a feeling that rinsing has concluded, and have insufficient sebum cleansing properties.